/*
 * Copyright (c) 2009, The MilkyTracker Team.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - Neither the name of the <ORGANIZATION> nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 *  AudioDriver_SDL.cpp
 *  MilkyPlay
 *
 *  Created by Peter Barth on 09.06.05.
 *
 *  Christopher O'Neill 16/3/06:
 *    fill_audio() rewritten to solve issues on certain systems
 *
 *
 */

#include "AudioDriver_SDL.h"

void SDLCALL AudioDriver_SDL::fill_audio(void* udata, Uint8* stream, int length)
{
    AudioDriver_SDL* audioDriver = (AudioDriver_SDL*)udata;

    if (length >> 2 != audioDriver->periodSize)
        fprintf(stderr, "SDL: Invalid buffer size: %i (should be %i), skipping..\n", length >> 2, audioDriver->periodSize);
    // See comment in AudioDriver_ALSA.cpp
    else
        audioDriver->fillAudioWithCompensation((char*)stream, length);
}

AudioDriver_SDL::AudioDriver_SDL () :
    AudioDriver_COMPENSATE()
{
}

AudioDriver_SDL::~AudioDriver_SDL ()
{
}

// On error return a negative value
// If the requested buffer size can be served return 0,
// otherwise return the number of 16 bit words contained in the obtained buffer
mp_sint32 AudioDriver_SDL::initDevice(mp_sint32 bufferSizeInWords, mp_uint32 mixFrequency, MasterMixer* mixer)
{
    SDL_AudioSpec wanted, obtained, saved;
    char name[32];
    mp_sint32 res = AudioDriverBase::initDevice(bufferSizeInWords, mixFrequency, mixer);
    if (res < 0)
        return res;

    wanted.freq = mixFrequency;
    wanted.format = AUDIO_S16SYS;
    wanted.channels = 2; /* 1 = mono, 2 = stereo */
    wanted.samples = bufferSizeInWords / wanted.channels; /* Good low-latency value for callback */

    wanted.callback = fill_audio;
    wanted.userdata = (void*)this;

    mp_sint32 finalWantedSize = wanted.samples * wanted.channels;

    // Some soundcard drivers modify the wanted structure, so we copy it here
    memcpy(&saved, &wanted, sizeof(wanted));

    if (SDL_OpenAudio(&wanted, &obtained) < 0)
    {
        memcpy(&wanted, &saved, sizeof(wanted));
        fprintf(stderr, "SDL: Failed to open audio device! (buffer = %d bytes)..\n", saved.samples * 4);
        fprintf(stderr, "SDL: Try setting \"Force 2^n sizes\" in the config menu and restarting.\n");
        return -1;
    }

    printf("SDL: Using audio driver: %s\n", SDL_AudioDriverName(name, 32));

    if (wanted.format != obtained.format)
    {
        fprintf(stderr, "SDL: Audio driver doesn't support 16-bit signed samples!\n");
        return -1;
    }

    if (wanted.channels != obtained.channels)
    {
        fprintf(stderr, "SDL: Failed to obtain requested audio format.  Suggested format:\n");
        fprintf(stderr, "SDL: Frequency: %d\nChannels: %d\n", obtained.freq, obtained.channels);
        return -1;
    }

    // fallback for obtained sample rate
    if (wanted.freq != obtained.freq)
        this->mixFrequency = obtained.freq;

    printf("SDL: Buffer size = %i samples (requested %i)\n", obtained.samples, finalWantedSize / wanted.channels);

    periodSize = obtained.samples;
    // If we got what we requested, return 0,
    // otherwise return the actual number of samples * number of channels
    return (bufferSizeInWords / wanted.channels == obtained.samples) ? 0 : obtained.samples * obtained.channels;
}

mp_sint32 AudioDriver_SDL::stop()
{
    SDL_PauseAudio(1);
    deviceHasStarted = false;
    return 0;
}

mp_sint32 AudioDriver_SDL::closeDevice()
{
    SDL_CloseAudio();
    deviceHasStarted = false;
    return 0;
}

mp_sint32 AudioDriver_SDL::start()
{
    SDL_PauseAudio(0);
    deviceHasStarted = true;
    return 0;
}

mp_sint32 AudioDriver_SDL::pause()
{
    SDL_PauseAudio(1);
    return 0;
}

mp_sint32 AudioDriver_SDL::resume()
{
    SDL_PauseAudio(0);
    return 0;
}